There are many undesired network applications that can be difficult to block, such as peer-to-peer (P2P) network applications, TOR, BITTORRENT, and botnets. These applications may mask their traffic, change port and destination addresses, or masquerade as other protocols, making firewalls only a partial solution to the problem of preventing the application from performing undesired or unauthorized communications. Unauthorized communications may result in the unauthorized exfiltration of sensitive data or the infiltration of malware.